engine overheat alarm

[Ash]

I am on the search for an engine "audible" overheat alarm but can't find a supplier any ideas or suggestions?

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[poggy]

What engine do you have. If it has a overheat sensor you can easily connect a buzzer to this as it swiches to earth on overheat. All you do is connect the positive connection for the buzzer to the ignition switch positive supply and then the earth from the buzzer to the overheat sensor on the engine.

If you don't have a sensor then you buy one from exhaust system companies.

Poggy

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[discovery2]

Index Marine Equipment (web site: www.indexmarine.co.uk) market an alarm, the sensor of which is attached to the exhaust pipe immediately after the cooling water injection. It is claimed that this arrangement will immediately detect an increase in temperature due to reduced water flow in the raw water system - before an increase in temperature might be detected by the temperature gauges.

David


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[maxi]

Try RS. They do a series of flat based sensors of different temperature settings, which can easily be attached to the exhaust elbow. Approx £1.90. Just add a buzzer and a bit of electric string.........

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[dickh]

The alternative for an overheat alarm is a cooling water "no flow" alarm. There was an article in PBO a couple of years back on how to fit this easily. The advantage is that it is much cheaper and as soon as the flow stops, the alarm sounds. I intend to fit one this year on my boat. If interested, I still have the article and can mail a copy to you if you PM me with your address.

<hr width=100% size=1>dickh
I'd rather be sailing... /forums/images/icons/smile.gif

 

[gtmoore]

This sounds interesting. Any idea how I might determine the correct temperature at which the buzzer should go off?

<hr width=100% size=1>Gavin

 

[rob]

hi

where do I find these companies?
thanks
regards rob

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[rob]

could you tell me who 'RS' is please as my sensor need replacing.

regards rob

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[Freebee]

radio spares

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[gtmoore]

Actually been digging around a bit - seems its 90 degrees C. It looks like the sensor used on the product from Index Marine (held on by Jubilee clips) is very similar to the Temp switch available from <A target="_blank" HREF=http://www.rswww.com>http://www.rswww.com</A>. In addition, RS do cheap buzzers too. Reckon it's about a fiver for the sensor and buzzer (and RS want to charge me the same to deliver it) - chuck in a couple of metres of bell wire and I'm there!

Thanks for the idea!

<hr width=100% size=1>Gavin

 

[anabel]

Halyard Marine manufacture an alarm that might suit. It has a sensor which is fitted inside the exhaust pipe close to the engine. It gives an audiable alarm as soon as it detects a rise in the exhaust temperature due to insufficient cooling water.

anabel

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[rickywright78]

Hi everyone - resurrecting this thread as I'm looking for a cost effective overheat alarm for my Volvo Penta MD2010. Any feedback on the DIY options mentioned above almost 20yrs on... did they work well? Thanks, Ricky

 

[harvey38]

SM007D

Easy to fit but to my mind, these are reactive being at the end of the cooling system, the water flow has decreased/stopped, the engine is still running so generating heat and will continue to build for a short while when the engine is shut down.

https://aqualarm.net/cooling-water-flow-c-2/

A more proactive approach at the start of the cooling system.

 

[Plum]

SM007D

Easy to fit but to my mind, these are reactive being at the end of the cooling system, the water flow has decreased/stopped, the engine is still running so generating heat and will continue to build for a short while when the engine is shut down.

My experience is the opposite. A sensor in the exhaust injection bend is, in effect, measuring exhaust temperature so as soon as the water stops flowing the rise in exhaust temperature is immediate giving just as much early warning as a flow sensor you recommend.

www.solocoastalsailing.co.uk

 

[pessimist]

My experience is the opposite. A sensor in the exhaust injection bend is, in effect, measuring exhaust temperature so as soon as the water stops flowing the rise in exhaust temperature is immediate giving just as much early warning as a flow sensor you recommend.

www.solocoastalsailing.co.uk

Another vote for the SM007D just fitted one and am very happy.

 

[Jodel]

Another vote here for Home: Silicon Marine although in my case i have the SM010 and I'm very happy with it. I find the typical running temperature on my MD2020 is 25 - 30c. The sensor is about 50cm downstream of the elbow.